Electrosurgical radio frequency energy transmission medium

ABSTRACT

A system and method for transmitting electro surgical energy from a generator to an electrosurgical instrument are provided. The electrosurgical system includes a generator adapted to generate electrosurgical energy for treating tissue. The generator includes one or more active output terminals which supply energy to the tissue. The active output terminals are operatively connected to one or more supply lines. The generator also includes one or more return output terminal which returns energy from the tissue. The return output terminals are operatively connected to at least one return line. The system also includes an electrosurgical instrument operatively connected to the one or more supply lines and one or more return electrodes operatively connected to one or more return lines. The system further includes an electrosurgical cable including one or more supply lines and one or more return lines. The one or more supply lines and one or more return lines are wound in a double helix fashion such that the electrical field along the cable is mitigated along the length thereof.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/523,888, filed on Sep. 20, 2006 now U.S. Pat. No. 7,819,865, theentire contents of which is incorporated herein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to an electrosurgical system and methodfor performing electrosurgical procedures. More particularly, thepresent disclosure relates to a system and method for effectivelytransmitting electrosurgical radio frequency energy from anelectrosurgical generator to a treatment site with reduced energy loss.

2. Background of Related Art

Electrosurgery involves application of high radio frequency electricalcurrent to a surgical site to cut, ablate, or coagulate tissue. Inmonopolar electrosurgery, a source or active electrode delivers radiofrequency energy from the electrosurgical generator to the tissue and areturn electrode carries the current back to the generator. In monopolarelectrosurgery, the source electrode is typically part of the surgicalinstrument held by the surgeon and applied to the tissue to be treated.A patient return electrode is placed remotely from the active electrodeto carry the current back to the generator.

In bipolar electrosurgery, one of the electrodes of the hand-heldinstrument functions as the active electrode and the other as the returnelectrode. The return electrode is placed in close proximity to theactive electrode such that an electrical circuit is formed between thetwo electrodes (e.g., electrosurgical forceps). In this manner, theapplied electrical current is limited to the body tissue positionedbetween the electrodes.

Transmission of electrosurgical energy to the treatment site, namelyfrom the electrosurgical generator to the instrument, is accomplishedvia an electrosurgical cable. During transmission an electrical field isgenerated through the cable and stray electrosurgical RF energy istypically emitted along the cable path, which tends to reduce treatmentenergy. Moreover, the electrical fields may interfere with the operationof other electronic equipment in the surgical arena, such as patientmonitoring equipment.

SUMMARY

The present disclosure relates to transmission of electrosurgical radiofrequency (“RF”) energy. An electrosurgical cable is disclosed havingclose proximity electrical field coupling between a supply and returntransmission lines. The coupling maximizes application of the RF energydelivered during surgery and minimizes the stray RF energy radiated bythe supply and return leads. Close proximity electrical field couplingsignificantly reduces the electrical field via field cancellationthereby increasing patient and surgeon safety. Coupling provides a lowloss inductive/capacitive (“LC”) transmission medium via athree-dimensional geometric orientation of the supply and return leads.The geometric orientation affects LC reactive components and reducesuncontrolled capacitive reactance caused by stray RF radiation. Inparticular, capacitive reactance is caused by antenna effect (e.g.,rapid discharge of stray RF energy) for transmission mediums shorterthan half a wavelength. Therefore, loss of stray RF energy is containedto a predetermined level which also reduces capacitive loading to theenergy source (e.g., electrosurgical energy).

According to one aspect of the present disclosure a system fortransmitting electrosurgical energy from a generator to anelectrosurgical instrument is disclosed. The electrosurgical systemincludes a generator adapted to generate electrosurgical energy fortreating tissue. The generator includes one or more active outputterminals which supply energy to the tissue. The active output terminalsare operatively connected to one or more supply lines. The generatoralso includes one or more return output terminal which returns energyfrom the tissue. The return output terminals are operatively connectedto at least one return line. The system also includes an electrosurgicalinstrument operatively connected to the one or more supply lines and oneor more return electrodes operatively connected to one or more returnlines. The system further includes an electrosurgical cable includingone or more supply lines and one or more return lines. The one or moresupply lines and one or more return lines are wound in a double helixfashion such that the electrical field along the cable is mitigatedalong the length thereof.

According to another aspect of the present disclosure an electrosurgicalcable is disclosed. The cable is configured to transmit electrosurgicalenergy from a source of electrosurgical energy to an electrosurgicalinstrument. The source of electrosurgical energy includes one or moreactive output terminals and one or more return output terminals. Theelectrosurgical cable includes one or more supply lines operativelyconnected to the active output terminals and one or more return linesoperatively connected to the return output terminals. The one or moresupply lines and the one or more return lines are wound in the doublehelix comprising geometrically of two congruent helixes having a sameaxis, differing by a translation along the axis such that the electricalfield along the cable is mitigated along the length thereof.

According to a further aspect of the present disclosure a method fortransmitting high frequency electrosurgical to an electrosurgicalinstrument is disclosed. The method includes the step of providing agenerator adapted to generate electrosurgical energy for treatingtissue. The generator includes one or more active output terminals whichsupply energy to the tissue. The active output terminals are operativelyconnected to one or more supply lines. An electrosurgical instrument isoperatively connected to the at least one supply line. The generatoralso includes one or more return output terminal which returns energyfrom the tissue. The return output terminals are operatively connectedto at least one return line. One or more return electrodes areoperatively connected to one or more return lines. The method alsoincludes the step of enclosing the one or more supply lines and one ormore return lines within an electrosurgical cable. The supply lines andthe return lines are wound in a double helix fashion such that theelectrical field along the cable is mitigated along the length thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure are described herein withreference to the drawings wherein:

FIG. 1 is a schematic block diagram of a prior art electrosurgicalsystem;

FIG. 2 is a schematic block diagram of one embodiment of anelectrosurgical system according to the present disclosure;

FIG. 3 is a perspective view of another embodiment of an electrosurgicalsystem according to one embodiment of the present disclosure;

FIG. 4 is a side, partial internal view of an endoscopic forcepsaccording to the present disclosure;

FIG. 5 is a schematic block diagram of a generator according to thepresent disclosure; and

FIG. 6 is a cross-sectional view of an electrosurgical cable accordingto the present disclosure.

DETAILED DESCRIPTION

Particular embodiments of the present disclosure are describedhereinbelow with reference to the accompanying drawings. In thefollowing description, well-known functions or constructions are notdescribed in detail to avoid obscuring the present disclosure inunnecessary detail. Those skilled in the art will understand that theinvention according to the present disclosure may be adapted for usewith either monopolar or bipolar electrosurgical systems and either anendoscopic instrument or an open instrument. It should also beappreciated that different electrical and mechanical connections andother considerations apply to each particular type of instrument.

The present disclosure provides for an electrosurgical transmissioncable wound in a double helix having a proximal geometric relationshipin three-dimensional physical space, to control the inductive andcapacitive components of the transmission cable and significantly reducethe capacitive leakage due to RF radiation. The transmission cableaccording to present disclosure being wound in a double helix minimizesthe stray RF radiation by reducing the transmitting antenna effect fortransmission mediums shorter than ½ wavelength.

FIG. 1 is a schematic illustration of a prior art electrosurgicalsystem. The system includes an electrosurgical generator 102 supplyingelectrosurgical radio frequency (“RF”) energy to a monopolarelectrosurgical instrument 110 via a supply transmission line 118. TheRF energy is returned to the generator 102 through a return electrode111, shown as a return pad via a return transmission line 119.Conventionally, the supply and return lines 118, 119 are oriented in arandom fashion and are not oriented with respect to each other tominimize stray RF energy emitted shown as lines 130, which occurs as RFenergy flows therethrough. Random placement of the supply and returnlines 118, 119 results in uncontrolled capacitive coupling due to strayRF radiation. Radiating RF energy source causes a transmitting antennaeffect caused by random orientation of the supply and return lines 118,119 during surgical procedures and forms an alternate RF leakage path tothe desired RF treatment energy.

FIG. 2 is a schematic illustration of an electrosurgical systemaccording to the present disclosure. The system is a monopolarelectrosurgical system that includes an electrosurgical instrument 10having one or more electrodes for treating tissue of a patient P.Electrosurgical RF energy is supplied to the instrument 10 by agenerator 2 via a supply line 18, which is operatively connected to anactive output terminal, allowing the instrument 10 to coagulate, sealand/or otherwise treat tissue. Energy is returned to the generator 2through a return electrode 11 and transmitted through a return line 19,which is operatively connected to a return output terminal. The supplyand return lines 18, 19 are enclosed within a cable 20.

System may include a plurality of return electrodes 11, which isbelieved to minimize the chances of damaged tissue by maximizing theoverall contact area with the patient P. In addition, the generator 2and the return electrode 11 may be configured for monitoring so called“tissue-to-patient” contact to insure that sufficient contact existstherebetween to further minimize chances of tissue damage. The generator2 may include a plurality of supply and return terminals andcorresponding number of transmission cables (e.g., two of each).

FIG. 3 shows an electrosurgical system 3 according to the presentdisclosure. The system 3 is a bipolar electrosurgical system thatincludes an electrosurgical forceps 12 having opposing jaw members. Theforceps 12 includes one or more shaft members 13 having an end effectorassembly 100 disposed at the distal end. The end effector assembly 100includes two jaw members 110, 120 movable from a first position whereinthe jaw members are spaced relative to on another to a closed positionwherein the jaw members 110 and 120 cooperate to grasp tissuetherebetween. Each of the jaw members includes an electricallyconductive sealing plate connected to an energy source (e.g., agenerator 2) that communicates electrosurgical energy through the tissueheld therebetween. Electrosurgical RF energy is supplied to the forceps12 by generator 2 via the supply line 18 operatively connected to theactive electrode and returned through the return line 19 operativelyconnected to the return electrode. The supply and return lines 18, 19are enclosed within cable 20.

As shown in FIG. 3, the forceps 12 is an endoscopic vessel sealingbipolar forceps. The forceps 12 is configured to support the effectorassembly 100. Those skilled in the art will understand that theinvention according to the present disclosure may be adapted for usewith either an endoscopic instrument or an open instrument. Moreparticularly, forceps 12 generally includes a housing 21, a handleassembly 42, a rotating assembly 80, and a trigger assembly 70, whichmutually cooperate with the end effector assembly 100 to grasp and treattissue. The forceps 12 also includes a shaft 13, which has a distal end14 that mechanically engages the end effector assembly 100 and aproximal end 16 that mechanically engages the housing 21 proximate therotating assembly 80. Handle assembly 42 includes a fixed handle 50 anda movable handle 40. Handle 40 moves relative to the fixed handle 50 toactuate the end effector assembly 100 and enable a user to grasp andmanipulate tissue as shown in FIG. 3.

Referring to FIGS. 3 and 4, the end effector assembly 100 includesopposing jaw members 110 and 120 having electrically conductive sealingplate 112 and 122, respectively, attached thereto for conductingelectrosurgical energy through tissue. More particularly, the jawmembers 110 and 120 move in response to movement of the handle 40 froman open position to a closed position. In open position the sealingplates 112 and 122 are disposed in spaced relation relative to oneanother. In a clamping or closed position the sealing plates 112 and 122cooperate to grasp tissue and apply electrosurgical energy thereto.Further details relating to one envisioned endoscopic forceps isdisclosed in commonly-owned U.S. application Ser. No. 10/474,169entitled “VESSEL SEALER AND DIVIDER.”

The jaw members 110 and 120 are activated using a drive assembly (notshown) enclosed within the housing 21. The drive assembly cooperateswith the movable handle 40 to impart movement of the jaw members 110 and120 from the open position to the clamping or closed position. Examplesof a handle assemblies are shown and described in the above identifiedapplication as well as commonly-owned U.S. application Ser. No.10/369,894 entitled “VESSEL SEALER AND DIVIDER AND METHOD MANUFACTURINGSAME” and commonly owned U.S. application Ser. No. 10/460,926 entitled“VESSEL SEALER AND DIVIDER FOR USE WITH SMALL TROCARS AND CANNULAS.”

Jaw members 110 and 120 also include insulators 116 and 126, whichtogether with the outer, non-conductive plates of the jaw members 110and 120 are configured to limit and/or reduce many of the knownundesirable effects related to tissue sealing, e.g., flashover, thermalspread and stray current dissipation.

In addition, the handle assembly 42 of this particular disclosureincludes a four-bar mechanical linkage that provides a unique mechanicaladvantage when sealing tissue between the jaw members 110 and 120. Forexample, once the desired position for the sealing site is determinedand the jaw members 110 and 120 are properly positioned, handle 40 maybe compressed fully to lock the electrically conductive sealing plates112 and 122 in a closed position against the tissue. The detailsrelating to the inter-cooperative relationships of the inner-workingcomponents of forceps 12 are disclosed in the above-cited commonly-ownedU.S. patent application Ser. No. 10/369,894. Another example of anendoscopic handle assembly which discloses an off-axis, lever-likehandle assembly, is disclosed in the above-cited U.S. patent applicationSer. No. 10/460,926.

The forceps 12 also includes a rotating assembly 80 mechanicallyassociated with the shaft 13 and the drive assembly (not shown).Movement of the rotating assembly 80 imparts similar rotational movementto the shaft 13 which, in turn, rotates the end effector assembly 100.Various features along with various electrical configurations for thetransference of electrosurgical energy through the handle assembly 20and the rotating assembly 80 are described in more detail in theabove-mentioned commonly-owned U.S. patent application Ser. Nos.10/369,894 and 10/460,926.

As best seen with respect to FIGS. 3 and 4, the end effector assembly100 attaches to the distal end 14 of shaft 13. The jaw members 110 and120 are pivotable about a pivot 160 from the open to closed positionsupon relative reciprocation, i.e., longitudinal movement, of the driveassembly (not shown). Again, mechanical and cooperative relationshipswith respect to the various moving elements of the end effector assembly100 are further described by example with respect to the above-mentionedcommonly-owned U.S. patent application Ser. Nos. 10/369,894 and10/460,926.

The forceps 12 may be designed such that it is fully or partiallydisposable depending upon a particular purpose or to achieve aparticular result. For example, end effector assembly 100 may beselectively and releasably engageable with the distal end 14 of theshaft 13 and/or the proximal end 16 of the shaft 13 may be selectivelyand releasably engageable with the housing 21 and handle assembly 42. Ineither of these two instances, the forceps 12 may be either partiallydisposable or reposable, such as where a new or different end effectorassembly 100 or end effector assembly 100 and shaft 13 are used toselectively replace the old end effector assembly 100 as needed.

With reference to FIGS. 2, 3 and 5, the generator 2 includes suitableinput controls (e.g., buttons, activators, switches, touch screen, etc.)for controlling the generator 2. In addition, the generator 2 mayinclude one or more suitable display screens for providing the surgeonwith variety of output information (e.g., intensity settings, treatmentcomplete indicators, etc.). The controls allow the surgeon to adjustpower of the RF energy, waveform, and other suitable parameters toachieve the desired waveform suitable for a particular task (e.g.,coagulating, tissue sealing, intensity setting, etc.). The instrument 10and/or forceps 12 may also include a plurality of input controls thatmay be redundant with certain input controls of the generator 2. Placingthe input controls at the instrument 10 and/or forceps 12 allows foreasier and faster modification of RF energy parameters during thesurgical procedure without requiring interaction with the generator 2.

FIG. 5 shows a schematic block diagram of the generator 2 having acontroller 4, a high voltage DC power supply 7 (“HVPS”) and an RF outputstage 8. The DC power supply 7 provides DC power to the RF output stage8, which then converts DC power into RF energy and delivers the RFenergy to the instrument 10 or forceps 12. The controller 4 includes amicroprocessor 5 operatively connected to a memory 6 which may bevolatile type memory (e.g., RAM) and/or non-volatile type memory (e.g.,flash media, disk media, etc.). The microprocessor 5 includes an outputport that is operatively connected to the HVPS 7 and/or RF output stage8 allowing the microprocessor 5 to control the output of the generator 2according to either open and/or closed control loop schemes. A closedloop control scheme may be a feedback control loop wherein the sensorcircuitry 11, which may include a plurality of sensing mechanisms (e.g.,tissue impedance, tissue temperature, output current and/or voltage,etc.), provides feedback to the controller 4. The controller 4 thensignals the HVPS 7 and/or RF output stage 8, which then adjusts DCand/or RF power supply, respectively. The controller 4 also receivesinput signals from the input controls of the generator 2 and/orinstrument 10. The controller 4 utilizes the input signals to adjustpower outputted by the generator 2 and/or performs other suitablecontrol functions thereon.

FIG. 6 shows a cross-sectional view of the cable 20. The cable 20includes the supply and return lines 18, 19. The supply and return lines18, 19 are operatively connected to the generator 2 via connectors 31,32 respectively. Connectors 31, 32 may be either of fixed or detachabletype allowing for the usage of multiple instruments and return electrodepads with the generator 2. The generator 2 and the connectors 31, 32 mayalso include identification means (e.g., bar codes or other codesdisposed on the connectors and scanners operatively connected to thegenerator, etc.) that identify the device operatively connected to theconnectors 31, 32. Upon connection of the connectors 31, 32, thegenerator 2 identifies the instrument and performs particularpreprogrammed operations (e.g., initialize procedure, set operatingparameters, adjust power settings, etc.).

The supply and return lines 18, 19 may be insulated. Various types ofinsulating materials may be used, which are within the purview of thoseskilled in the art. The supply and return lines 18, 19 extend from theconnectors 31, 32 respectively for a distance A, which is optimallycontrolled by the location of connectors 31, 32 and is between fromabout 0.1 inches to about 6 inches. The lines 18, 19 are then helixwound in a wound portion 35, which be about 7 feet or more dependingupon a desired cable inductance and capacitance. Alternatively, thewound portion 35 may extend from the connectors 31, 32 without extendingthe supply and return lines 18, 19 for the distance A.

The wound portion 35, along cable length B, can be of any lengthdepending on geometric configuration and physical properties (e.g.,tensile strength, flexibility, etc.) of materials used in manufacturingof cable components. More specifically the lines 18, 19 are oriented ina double helix which includes two congruent helixes with the same axis,differing by a translation along the axis. The lines 18, 19 may beoriented in a plurality of other arrangements which wrap the lines 18,19 around themselves. The arrangement of the lines 18, 19 in a doublehelix orients the opposing electrical fields generated by theelectrosurgical RF energy passing therethrough to mitigate and/or cancelout thereby minimizing the amount of lost stray electrical RF energy.

The lines 18, 19 are wound within the cable 20 around a dielectricinsulator 37, which provides support for the lines 18, 19, an insulativesheath 39 covers the lines 18, 19. The insulator 37 and the sheath 39may be of the same type. The lines 18, 19 may comprise wire that has aninductance rating at 473 kHz of 7.37 μH and A, capacitance at 1 MHz of32.0 PF to yield a cable self resonance of 10.4 MHz. The wire may be 26gauge and 15 kV rated.

With reference to FIG. 6 and the portion 35, the distance D, whichrepresents the distance between one apex of one helix and a nearest apexof another helix, may be about ½ inch. The distance E, which is thedistance between two apexes of the same helix may be about 1 inch. Theouter diameter F of the cable 20 may be about ⅜ of an inch.

Cable 20 as illustrated in FIG. 6, provides a transmission medium todeliver RF energy from the generator 20 to a tissue site. The cable 20represents one example of a preferred embodiment for the RF transmissionmedium, which reduces the radiated RF electrical field and maximizes theapplied clinical treatment energy delivered to the tissue site. Thedimensions A, B, C, D, E and F of FIG. 6 form a unique proximalgeometric relationship in three dimensional space to control theelectrical field coupling between the active and return output terminalsof the generator 20 to significantly reduce the Volts per meterelectrical field radiation by field cancellation.

The physical dimensions A, B, C, D, E and F are interdependent andoptimized to provide a low loss inductive and capacitive transmissionmedium, which in addition to controlling the electrical field, reducesuncontrolled capacitive coupling caused by stray RF radiation. Inparticular the following equations (1) and (2) illustrate theinterdependent relationship of dimensions A, B, C, D, E and F withrespect to inductive and capacitive properties of the cable 20.Inductance=B(10.16×10^−9)Ln[(2×D)/d)]+2(A+C)(μH/in. for specifiedwire)  (1)Capacitance=[(B×(0.7065×10^−12))/Ln[(2×D)/d]]er  (2)In equations (1) and (2) d denotes diameter of the wire (e.g., supplyand return lines 18, 19), er denotes the dielectric constant of the wireinsulator. Further, E=2×D, the ratio of E to D allows to establish acontinuum of the helix configuration and F=k×D, where k is a constantfrom about 0.5 to about 1.5.

At the distal end of the portion 35, the lines 18, 19 are unwound andare operatively connected to device connectors 33, 34 respectively. Thelines 18, 19 extend a distance C from the portion 35 to the connectors33, 34 in an unwound state for approximately 2.5 feet. The initiallength A of the lines and the unwound state length C are maintainedrelatively consistent with varying lengths of wire with length of thewound portion 35 varying for different overall lengths.

In bipolar surgery, the connectors 33, 34 may be situated on the forceps12. In monopolar surgery, the connector 33 is operatively connected tothe instrument 10 and the connector 34 is connected to the returnelectrode 11. As discussed above, in situations where a plurality ofreturn electrodes are used, the return line 19 may split intocorresponding number of leads to operatively connect all of the returnelectrodes 11 to the generator 2. With monopolar surgery the length Cfor line 18 may lengthen greater than 2.5 feet with a correspondingdecrease in line 19 to accommodate manipulation of surgical instrumentin the operating site.

The cable 20 according to the present disclosure orients the supply andreturn lines 18, 19 so that the electrical fields generated therethroughare canceled, thereby reducing the amount of leaked stray RF energy.More specifically, placement and orientation of the lines 18, 19 in themanner discussed above provides for close proximity of electrical fieldsgenerated during transmission of electrosurgical RF energy and maximizesamount of energy delivered to the treatment site. Reducing theelectrical fields also increases safety of personnel and the patient.

Reduced RF radiation decreases capacitive and RF field leakage andimproves RF control of the delivered energy. Reduced RF radiation alsodecreases RF transmission loss and improves efficiency of the generator2 by reducing RF harmonic component, minimizing corruption of the RFsource and reducing peripheral conductive and radiative emissions.Further, reducing RF radiation also decreases the RF noise to additionalequipment found in the room, such as patient monitoring equipment.

While several embodiments of the disclosure have been shown in thedrawings and/or discussed herein, it is not intended that the disclosurebe limited thereto, as it is intended that the disclosure be as broad inscope as the art will allow and that the specification be read likewise.Therefore, the above description should not be construed as limiting,but merely as exemplifications of particular embodiments. Those skilledin the art will envision other modifications within the scope and spiritof the claims appended hereto.

1. An electrosurgical system, comprising: a generator adapted togenerate electrosurgical energy for treating tissue, the generatorincluding at least one active output terminal that supplies energy tothe tissue, the at least one active output terminal operativelyconnected to at least one supply line, the generator also including atleast one return output terminal that returns energy from the tissue,the at least one return output terminal operatively connected to atleast one return line; an electrosurgical instrument operativelyconnected to the at least one supply line; at least one return electrodeoperatively connected to the at least one return line; and anelectrosurgical cable including the at least one supply line and the atleast one return line, a portion of the at least one supply line and aportion of the at least one return line being wound in a double helixsuch that the electrical field along the length of the cable is reduced,wherein at least one parameter of the wound portion of the cable and atleast one parameter of an unwound portion of the cable are configured tocontrol the electrical field coupling between the at least one supplyline and the at least one return line.
 2. The electrosurgical system ofclaim 1, wherein the at least one parameter of the wound portion of thecable is one or more of the parameters selected from the groupconsisting of (a) an apex distance between an apex of a first helix anda nearest apex of a second helix, (b) a distance between two apexes ofthe same helix, (c) an outer diameter of the cable, and (d) a length ofthe wound portion of the cable.
 3. The electrosurgical system of claim1, wherein the at least one parameter of the unwound portion of thecable is one or more of the parameters selected from the groupconsisting of (a) a distance between a first end of the wound portion ofthe cable and the output terminals of the generator and (b) a distancebetween a second end of the wound portion of the cable and at least oneconnector of the electrosurgical instrument.
 4. The electrosurgicalsystem of claim 1, wherein an apex distance between an apex of a firsthelix and a nearest apex of a second helix is about half a distancebetween two apexes of the same helix and the first and second helixesare disposed a predetermined distance apart as a function of the apexdistance.
 5. The electrosurgical system of claim 1, wherein the doublehelix includes two congruent helixes having a same axis and separated apredetermined distance from each other along the axis.
 6. Theelectrosurgical system of claim 1, wherein the at least one supply lineand the at least one return line are covered by a sheath.
 7. Theelectrosurgical system of claim 1, wherein the at least one supply lineand the at least one return line are wound around a dielectricinsulator.
 8. An electrosurgical system of claim 1, wherein theelectrosurgical instrument is an electrosurgical forceps including atleast one shaft member having an end effector assembly disposed at adistal end thereof, the end effector assembly including two jaw membersmovable from a first position in spaced relation relative to one anotherto at least one subsequent position wherein the jaw members cooperate tograsp tissue therebetween, each of the jaw members including anelectrical sealing plate, wherein one electrical sealing plate isoperatively connected to the at least one supply line and anotherelectrical sealing plate is operatively connected to the at least onereturn line.
 9. An electrosurgical cable configured to transmitelectrosurgical energy from a source of electrosurgical energy to anelectrosurgical instrument, the source of electrosurgical energy havingat least one active output terminal and at least one return outputterminal, the electrosurgical cable comprising: at least one supply lineoperatively connected to the at least one active output terminal and atleast one return line operatively connected to the at least one returnoutput terminal, wherein a portion of the at least one supply line and aportion of the at least one return line are wound in a double helixhaving a proximal geometric relationship in three-dimensional physicalspace, wherein at least one parameter of the wound portion of the cableand at least one parameter of an unwound portion of the cable areconfigured to control the electrical field coupling between the at leastone supply line and the at least one return line.
 10. Theelectrosurgical cable of claim 9, wherein an apex distance between anapex of a first helix and a nearest apex of a second helix are abouthalf a distance between two apexes of the same helix, wherein the firstand second helixes are disposed a predetermined distance apart as afunction of the apex distance.
 11. The electrosurgical cable of claim 9,wherein the double helix includes two congruent helixes having a sameaxis and separated a predetermined distance from each other along theaxis.
 12. The electrosurgical cable of claim 9, wherein theelectrosurgical instrument is a monopolar electrosurgical instrumentoperatively connected to the at least one supply line, and wherein atleast one return electrode is operatively connected to the at least onereturn line.
 13. The electrosurgical cable of claim 9, wherein theelectrosurgical instrument is an electrosurgical forceps comprising atleast one shaft member having an end effector assembly disposed at adistal end thereof, the end effector assembly including two jaw membersmovable from a first position in spaced relation relative to one anotherto at least one subsequent position wherein the jaw members cooperate tograsp tissue therebetween, each of the jaw members including anelectrical sealing plate, wherein one electrical sealing plate isoperatively connected to the at least one supply line and anotherelectrical sealing plate is operatively connected to the at least onereturn line.
 14. The electrosurgical cable of claim 9, wherein the atleast one supply line and the at least one return line are wound arounda dielectric insulator.
 15. A method for transmitting high frequencyelectrosurgical energy to an electrosurgical instrument, the methodcomprising: providing a generator adapted to generate electrosurgicalenergy for treating tissue, the generator including at least one activeoutput terminal that supplies energy to the tissue, the at least oneactive output terminal operatively connected to at least one supplyline, wherein an electrosurgical instrument is operatively connected tothe at least one supply line, the generator also including at least onereturn output terminal that returns energy from the tissue, the at leastone return output terminal operatively connected to at least one returnline, wherein at least one return electrode is operatively connected tothe at least one return line; enclosing the at least one supply line andthe at least one return line within an electrosurgical cable, a portionof the at least one supply line and a portion of the at least one returnline being wound in a double helix fashion such that the electricalfield along the length of the cable is reduced; and configuring at leastone parameter of the wound portion of the cable and at least oneparameter of an unwound portion of the cable to control the electricalfield coupling between the at least one supply line and the at least onereturn line.
 16. The method of claim 15, wherein an apex distancebetween an apex of a first helix and a nearest apex of a second helix isabout half a distance between two apexes of the same helix and the firstand second helixes are disposed a predetermined distance apart as afunction of the apex distance.
 17. The method of claim 15, wherein theelectrosurgical instrument is a monopolar electrosurgical instrumentoperatively connected to the at least supply line, and wherein at leastone return electrode is operatively connected to the at least one returnline.
 18. The method of claim 15, further comprising the step of:providing an electrosurgical forceps comprising at least one shaftmember having an end effector assembly disposed at a distal end thereof,the end effector assembly including two jaw members movable from a firstposition in spaced relation relative to one another to at least onesubsequent position wherein the jaw members cooperate to grasp tissuetherebetween, each of the jaw members including an electrical sealingplate, wherein one electrical sealing plate is operatively connected tothe at least supply line and another electrical sealing plate isoperatively connected to the at least return line.
 19. The method ofclaim 15, wherein the at least one supply line and the at least onereturn line are wound around a dielectric insulator.